ReACL process is non-destructive by definition and will not touch user profiles on Windows 10/11 and RDSH servers. Actual repermission of users' profiles is happening during the Cutover process, which involves running ReACL on users' profiles prior to joining the target domain.
In addition, this ReACL/Cutover process also changes the source user's SID key under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList to its target SID. This SIDs relationship is established by the dirsync process during the workflow Match step.
